Early Impact of Agropastoral Activities and Climate on the Littoral Landscape of Corsica Since Mid-Holocene
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Early impact of agropastoral activities and climate on the littoral landscape of Corsica since mid-Holocene Marc-Antoine Vella, Valérie Andrieu-Ponel, Joseph Cesari, Franck Leandri, Kewin Peche-Quilichini, Maurice Reille, Yoann Poher, François Demory, Doriane Delanghe, Matthieu Ghilardi, et al. To cite this version: Marc-Antoine Vella, Valérie Andrieu-Ponel, Joseph Cesari, Franck Leandri, Kewin Peche-Quilichini, et al.. Early impact of agropastoral activities and climate on the littoral landscape of Corsica since mid-Holocene. PLoS ONE, Public Library of Science, 2019, 14 (12), pp.e0226358. 10.1371/jour- nal.pone.0226358. hal-02421019 HAL Id: hal-02421019 https://hal.archives-ouvertes.fr/hal-02421019 Submitted on 20 Dec 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Early impact of agropastoral activities and climate on the littoral lands... https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0226358 Marc-Antoine Vella , Valérie Andrieu-Ponel, Joseph Cesari, Franck Leandri, Kewin Pêche-Quilichini, Maurice Reille, Yoann Poher, François Demory, Doriane Delanghe, Matthieu Ghilardi, Marie-Madeleine Ottaviani-Spella Published: December 19, 2019 https://doi.org/10.1371/journal.pone.0226358 Abstract A multidisciplinary study (geomorphology, sedimentology and palynology) shows that the landscapes of the southwest coast of Corsica have been deeply modified by humans and the climate since 3000 BC. Significant and rapid landscape transformations are recorded between the Chalcolithic and the Middle Bronze Ages (3000–1300 BC). Several major (2.2 ka BC, 1.2 ka BC) and local (3000 BC) detrital events affected the Taravo Lower Valley in relation to global climatic changes and anthropic activities. The vegetation dynamics since 3000 BC show alternating phases of agriculture and abandonment until the complete disappearance of the original forest populations in the vicinity of the Canniccia Marshes. An early phase of Olea cultivation is recorded between 2900 and 2300 BC. Plant macro-remains indicate that cereals, vine and many species of Fabaceae were cultivated in the nearby of the archaeological sites during the middle to the late Chalcolithic Age. The event of 2.2 ka BC corresponds to an abandonment phase in the lower Taravo Valley. Pastoralism dominated agricultural activities between 2200 and 1700 BC. During Roman times, agriculture is characterized by olive and vine cultivation. A new peak of pastoralism and the cultivation of Castanea are noted during invasion times (500 to 1000 AD), showing that invasions didn’t disturb agricultural activities in the Taravo Valley. During the Pisa Period (end of the 9th C. to then end of 13 th C. AD), pastoralism declined and vine and cereals were cultivated in the very nearby of the Canniccia Marshes. During the Genoa Period upwards (end of the 13th C. to 1769 AD), a decline in agriculture and a recrudescence of the forest (maquis and pine) are recorded, leading to the settlement of a present-day vegetal landscape dominated by an Erica arborea maquis. Citation: Vella M-A, Andrieu-Ponel V, Cesari J, Leandri F, Pêche-Quilichini K, Reille M, et al. (2019) Early impact of agropastoral activities and climate on the littoral landscape of Corsica since mid-Holocene. PLoS ONE 14(12): e0226358. https://doi.org/10.1371/journal.pone.0226358 Editor: Andrea Zerboni, Universita degli Studi di Milano, ITALY Received: June 28, 2019; Accepted: November 25, 2019; Published: December 19, 2019 Copyright: © 2019 Vella et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability: All relevant data are within the manuscript and its Supporting Information files. Funding: This work was supported by Ministry of Culture, DRAC/SRA Corse, ARTEMIS Program. MISTRALS/Archeomed /INEE. FIR (Fonds Incitatifs de Recherche, Université de Provence). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist. Introduction Paleoenvironmental studies of Mediterranean Valleys have been widely developed since the late 1960s [1–10]. They confirm the importance of fluvial and lake environments, in order to better understand Holocene landscape changes [9, 11–17]. They also attest to the presence of periods of global rapid climate change (RCC) observed during the recent Holocene Epoch (2.2 ka BC, 1.2 ka BC, Little Ice Age (LIA, 1450–1850 AD) [9, 17–20]. These RCCs could have directly modified yields and agricultural practices, leading to major societal reorganizations, especially during the Bronze Age. These studies also demonstrated an increasing anthropogenic impact on Mediterranean ecosystems since the Neolithic Age [21]. However, few works exist about the Mediterranean islands on Holocene alluvial paleoenvironments. Most of actual references are largely limited to the Eastern Mediterranean where major civilizations arose (Minoan, Mycenian and Greeks). Cyprus [22–27], Euboea [28–32], and the north coast of Greece [20, 33] represent the most studied regions. Concerning the central Mediterranean island, several studies restitute the evolution of Sicilian lakes levels during the late Holocene [34–38]. A smaller number of studies treat the paleogeographic evolution of the littoral valleys in Malta [36, 39]. Finally, significant results for the Western Mediterranean were obtained in Sardinia [40] and Corsica [41–46] (Fig 1A). 1 sur 20 20/12/2019 à 10:58 Early impact of agropastoral activities and climate on the littoral lands... https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0226358 Fig 1. Location map of the study area. The data for the DEM (SRTM 3) was acquired from the USGS Earth Explorer Map Viewer (public domain). The data for the geology was acquired from the BRGM (Bureau de Recherches Géologiques et Minières) Map Viewer (public domain), modified. A: Corsica within the western Mediterranean area. B: Topographic map of Corsica. Reference site: b. Bastani, c. Creno, dS, Étang del Sale, f. Fango, s. Saleccia, Sp, Spizicciu. C: Location and geology of the Taravo drainage basin. https://doi.org/10.1371/journal.pone.0226358.g001 In contrast, topics related to vegetation history and human impact on Mediterranean island ecosystems are more developed [47]. Pollen studies undertaken in Sicily ([35, 48–49], Crete [50–51], Malta [36, 52–53] and Corsica [54–57] (Fig 1A) helped in reconstructing vegetation history since the end of the Last Glacial Maximum (LGM). Combined with micro-charcoal analysis in Corsica [58–63], these studies related human activities, such as fire signals, to vegetation change since the early Neolithic Age. This influence resulted in the modification of the vegetation composition/morphology, domestication and introduction of new species. However, from paleoenvironmental, geomorphological and geoarchaeological points of view, the alluvial plains of Corsica are relatively little studied (Fig 1A). Previous research on Quaternary, and Holocene sedimentary dynamics, in particular, remains fairly general [64–65] and makes no reference to possible impacts on population dynamics or relations to vegetation history. This article focuses on the Taravo Valley where, since the 1950s, several archaeological research programs allowed to outline the main stages of cultural evolutions since the Mesolithic Age. However, they required more paleoenvironmental analysis especially for periods of major archaeological occupation of the island as few cross-combined approaches were realized on main archaeological sites. For the present study, three cores were drilled in the Canniccia Marshes where a previous deep core (CAN REILLE) was realized in 1998 [66] for pollen analyses (S1 Fig, Table 1, Fig 2A and 2B). In this article, only the first 10 m of CAN REILLE are presented. Table 1. Geographic coordinates of the boreholes. https://doi.org/10.1371/journal.pone.0226358.t001 Fig 2. Sites implantation within the lower Taravo Valley. The data for the DEM (BdAlti® ) and orthorectified aerial pictures was acquired from the IGN (Institut National de l’Information Géographique et Forestière; ®IGN2019) Map Viewer (public domain). Elevation contours (10 m) are derived from ®BdAlti25 data. The data for the geology was acquired from the BRGM Map Viewer (public domain), modified. A: Simplified geology of the Lower Taravo Valley and location of Fig. 2B. B: Orthorectified aerial picture of Canniccia marshes. https://doi.org/10.1371/journal.pone.0226358.g002 CAN 1 (5.8 m), CAN 2 (8.5 m) and CAN 3 (3.2 m) were drilled in 2008 and studied for sediment properties. Preliminary results from recent geoarchaeological studies [42, 45–46] highlighted several detrital events in the Canniccia Marshes, just beneath the archaeological site of I Calanchi/Sapar’Alta. For the purpose of this article, the chronostratigraphic